Strainer



W. A. GORDON May 1, 1934.

STRAINER Filed Feb. 20. 1931 2 Sheets-Sheet 1 y 1934. w. A. GORDON 1,956,720

STRAINER Filed Feb. 20. 1931 2 Sheets-Sheet 2 F '15- z I '7 7T /7/ by 'inlgnunnw WT Y V Y j a I minimum f j ,p V ////l///I 1 177m vi, U A w 4 %Wa%m,

STATES ATM? Fifiiii STRAINER William A. Gordon, Shelton, Conn, assignor to Farrel-Birmingham Company, Incorporated, Ansonia; Conn, a corporation of Connecticut Application February 20, 1931, Serial No. 517,172

7 Claims. (Cl. 146-174) This invention relates to strainers and aims to Referring to the drawings, let A indicate the provide certain improvements therein. bed of the machine having a front housing B, the

In the working of rubber compounds it is cusinterior of which is formed as a cylinder 0, which tomary to force the plastic compound through sis properly waterjacketed, the cylinder 0 being called strainers which are provided with a mulpreferably constructed separate from the hous- 6O tiplicity of fine openings, the compounds being ing and adapted to fit therein. D is the pressure forced through the strainers under very considscrew which has a portion extending under a erable pressure. In such straining machines hopper E, as best seen in Fig. 3, the shaft of the pressure is put upon the plastic compounds usualscrew extending backwardly for a suitable drive 10 ly by a pressure screw, which receives the mateindicated as comprising a large gear F turned 65 rial from a hopepr and conveys it along a cylby a small gear G mounted upon a shaft II which inder to the end thereof where the strainer head is rotated by a larger gear I, meshing with a is mounted. In some of the prior constructions pinion J mounted upon a shaft K, which receives the strainer head has been provided with perfomotion from any suitable source of power transrations on its end face. The area of such end mitted through a shaft L which is connected with 70 face is, however, limited, and for this reason in the shaft K through a flexible connection M. At some constructions the strainer head has been the rear of the hopper the pressure screw shaft is constructed as a cap with perforations in its side provided with a pinion N, meshing with a simior cylindrical walls so that a larger area of strainlar pinion O mounted upon a counterhaft P er surface is available. Neither of these expediwhich extends forwardly and turns a feed roll Q 75 cuts has resulted in securing the desired output, located in the hopper E of the machine. By refsince the compound is stiff and requires a very erence to Fig. 2, it will be seen that I provide a considerable pressure to force it through the fine scraper R which clears the face of the feed roll openings required, and in each of the cases men- Q, the scraper R being yieldingly mounted upon tioned the pressure on the compound has been a plate S, but being normally held in engageso exerted largely in the direction of length of the ment with the feed roll Q by a spring T surscrew. rounding a shaft U which is screwed into the According to the present invention I provide a scraper.

construction which in its preferred form utilizes The form of screw which I prefer to utilize is a strainer having lateral openings, and I provide of the type which contacts closely with its cylin- 85 means for imparting to the compound a pressure der, and is so shaped as to provide the maximum which is very largely transverse to the axis of the degree of compression in lines which are parallel pressure screw. The means for accomplishing with the axis of the screw, or in other words, one this purpose are best located at the end of the which is adapted to feed the material forward unpressure screw and within the strainer head, der pressure to the best advantage. I have hence '90 although other constructions are not excluded. shown a screw with a thread whose front walls The Simplest form of the v e comprises a latare substantially transverse to the axis of the eral forcing means formed integrally with the screw, screw at h end thereof. so that it is driven by The strainer section of the machine, which is 40 the screw. The invention also includes certain that to which my invention chiefly t 1 m. other features of construction which will be here- (mated as a Whole by the reference letter This ina'ftel' more fully P mstrainer section comprises a strainer W having the diawmgsy Whlch lllustmte one mm 0f a multiplicity of lateral openings distributed the mventmm throughout its circular wall, so as to provide lat- 45 fi f g i fggggg i g g g g: eral egress of the material. The important fea- C em 0 yl g p ture of the invention, however, is the provision of vention. v do dt Ci t k n on the a forcing member ,W 10 1S csigne o ieceive Flg 2 IS an enlarbed Se t on a E the compound as 1t is compressed axially by the line 2-2 in Fig. 1. a b 1 50 Fig. 3 is an enlarged longitudinal section of the l and t0 force 1L mac 9 a ladle rection. The means for accomplishing this purscrew and part of the machine.

Fig 4 is a section of the strainer head taken on pose are subgect to considerable mod1ficat1on, but

the line 44 in Fig. 3, and still further enlarged, in the drawings I have illustrated the form which Fig. 5 is a view on a smaller scale of the screw I p e to detached from the machine. In this form I provide one or more blades Y,

each of which has a curved face Z, which in connection with the strainer provides a wedge-shaped space A, the base of which leads as the screw is rotated, and the apex of which follows. This is best shown in Fig. 4, wherein the section X is illustrated as rotating in the direction of the arrow. One such blade might be used, but I prefer two, as shown, or more, the blades being symmetrically arranged so as to equalize the reaction thrusts. t will be observed that the material which is being piled up in the end of the cylinder by the main portion of the screw D is, when it reaches the strainer head, subjected to the wedging action of the blades Y so that it is given a powerful radially outward compression, thus forcing it through the strainer directly and positively by mechanical means, as distinguished from the pressure of the material behind it, as is now the case. It is useful if the hub supporting the blades Y be formed with a tapered surface, such as shown at B (Fig. 3) by which the material is guided more or less into a radial path between the blades.

The details of the strainer proper are a subordinate feature of the invention. I have shown the strainer casing in the form of a cap C, the multiplicity of holes or outlets D being more or less radially arranged. The cap C is shown as connected to the housing B by a ring E which overlies a flange on the cap, and is itself held in place by bolts F. In Fig. 4 I have shown the construction I prefer to use for the actual screening section, which construction comprises a threepart lining extending along the inner side of the cap C, this lining comprising two cylinders of relatively coarse meshed wire screening designated by the reference letters G and H. Interposed between the two is a much finer screen, the number of meshes of which to the square inch depends upon the character of the material to be strained. [his intermediate screen is lettered I. This construction provides asupport for what may be termed the actual screen, namely, the sleeve I, both inside and outside.

t is, of course, understood that the invention is useful in straining crude rubber or any other materials which may require similar treatment.

While I have shown and described one form of the invention, it will be understood that I do not wish to be limited thereto, since various changes may be made therein without departing from the spirit of the invention.

What I claim is:

1. In a strainer for rubber compounds or the like, a rotatable forcing member adapted to receive material, fed under axial pressure, and to force said material laterally through lateral straining means, said forcing member comprising longitudinally disposed blades on a tapered hub having its minimum diameter at the receiving extremity thereof, the taper of the hub being substantially free of laterally disposed convolutions.

2. A device according to claim 1 in which the hub is concavely tapered.

3. A device according to claim 1 in which the blades are disposed upon the tapered portion of the hub.

4. A device according to claim 1 in which the inner portions of the leading faces of the blades are in advance of the outer portions thereof in the path of rotation.

5. A device according to claim 1 in which the leading faces of the blades are convexly curved, the inner portions of said faces being in advance of the outer portions thereof in the path of rotation.

6. A device according to claim 1 in which the blades are substantially parallel to the axis of the hub.

7. A straining mechanism for rubber compounds or the like comprising a heavy casing having a cylindrical wall, a straining sleeve at the end of said cylinder, a rotatable elongated conveyor member mounted within said cylinder and sleeve, the portion of said conveyor member within the cylinder having substantially laterally disposed convolutions adapted to force material longitudinally toward the straining sleeve, the portion of said conveyor member within the straining sleeve having its hub flared to its maximum diameter toward the extreme end thereof and having longitudinally disposed blade-like protuberances on said flared portion whereby said flared portion and blade-like protuberances operate to guide and force the material outwardlythrough the straining sleeve, the flared portion of the hub being substantially free of laterally disposed convolutions.

WILLIAM A. GORDON. 

